JP5447283B2 - Optical scanner and image forming apparatus - Google Patents

Description

  The present invention relates to an optical scanner for performing drawing or the like by optical scanning, and an image forming apparatus including the optical scanner.

  Conventionally, as disclosed in Patent Document 1, an electromagnetic actuator having a function as an optical scanner is known. The electromagnetic actuator includes an insulating substrate provided with a pair of permanent magnets, and a scanner main body positioned between the pair of permanent magnets and supported by the insulating substrate. The scanner main body is a frame-shaped support portion. And a so-called gimbal structure having a frame-shaped outer movable plate provided inside the support portion and an inner movable plate provided inside the outer movable plate and having a total reflection mirror. The outer movable plate is connected to the support portion via a pair of first torsion bars, and the inner movable plate is connected to the outer movable plate via a pair of second torsion bars orthogonal to the first torsion bar. It is connected. Each of the outer movable plate and the inner movable plate is provided with a planar coil.

  In the electromagnetic actuator having such a configuration, the outer movable plate and the inner movable plate are centered on the first torsion bar by applying a magnetic field generated from each planar coil by energization and a magnetic field between the pair of permanent magnets. The inner movable plate rotates about the second torsion bar as the central axis. Thereby, the electromagnetic actuator can control the reflection direction of the light incident on the total reflection mirror, and functions as an optical scanner.

JP-A-8-322227

  However, in the related art, the electromagnetic actuator also rotates and moves in the extending direction of the central axis of the second torsion bar in conjunction with the rotation of the first torsion bar. For this reason, the control for rotating the first torsion bar and the second torsion bar to direct the total reflection mirror in a predetermined direction has been complicated. Further, the magnetic field generated from the planar coil provided on the outer movable plate of the electromagnetic actuator and the magnetic field generated from the planar coil provided on the inner movable plate are likely to interfere with each other. The rotation around the central axis of the torsion bar or the second torsion bar may be different from the intended rotation. Therefore, in the conventional optical scanner configured as an electromagnetic actuator, there is a problem that it is difficult to stably and freely rotate the total reflection mirror of the inner movable plate, and it cannot be easily performed.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 An optical scanner according to this application example includes a light reflection member having a light reflection surface, a support member that supports the light reflection member, and a movable portion that holds the light reflection member via the support member. A pair of movable beams each extending in parallel with the light reflecting surface from the movable portion and having a bent portion at an intermediate portion thereof, and being directly connected to the movable beam and applying displacement to the movable portion via the movable beam. A first drive device having a displacement portion and provided at each end in the extending direction of the movable beam; and extending from the displacement portion, parallel to the light reflecting surface and extending in the movable beam A pair of drive beams orthogonal to each other, a support frame for fixing the drive beams, and a second drive device that directly applies a displacement different from the first drive device to the movable part. It is characterized by being.

  According to this optical scanner, the light reflecting surface is displaced in conjunction with the movable portion, and reflects incident light in an arbitrary direction. The movable portion is displaced following the operation of the movable beam driven by the displacement portion of the first driving device. Here, in a non-driving state, the movable beam has a form extending along a first axis which is one axis together with the displacement portion on a plane parallel to the light reflection surface, It is supported by a driving beam extending in a direction orthogonal to the movable beam on a plane parallel to the light reflecting surface. That is, when the displacement portion rotates around the drive beam, the pair of movable beams sandwiching the movable portion respectively rotate, thereby displacing the movable portion. And the bending part provided in the movable part has a function which bends flexibly according to each rotation of a movable beam, and displaces a movable part reliably along this 1st axis. Further, the optical scanner includes a second driving device, and the second driving device has a configuration in which the movable portion itself has the function of the displacement portion of the first driving device. The movable part is displaced along the second axis in a different direction. That is, in the second drive device, the movable part can be displaced directly without the movable beam and the drive beam. At this time, the movable beam and the bent portion serve to avoid the influence of the displacement applied to the movable portion by the second drive portion from reaching the displacement portion of the first drive device. Similarly, the movable beam and the bent portion function to avoid the influence of the displacement by the first driving unit from reaching the second driving device. As a result, the optical scanner can stably and individually cope with the displacement applied to the first driving device or the second driving device individually along the first axis or the second axis. And can be displaced freely. In addition, since the second drive device has a configuration that does not include a movable beam and a drive beam, the optical scanner can be downsized.

  Application Example 2 In the optical scanner according to the application example described above, the first driving device includes a first permanent magnet provided in the displacement portion and a coil that generates a magnetic field that acts on the first permanent magnet. And a second driving unit including a second permanent magnet provided in the movable unit, and a second driving unit including a coil that generates a magnetic field acting on the second permanent magnet. It is preferable to have.

  According to this configuration, the first drive device generates a magnetic field from the coil of the first drive unit with respect to the first permanent magnet provided in the displacement unit, and the pole side of one of the first permanent magnets is coiled. The displacement portion is configured to rotate by being attracted to. The movable beam is also rotated by the rotation of the displacement portion, and the movable portion is displaced along the first axial direction. On the other hand, the second drive unit generates a magnetic field from the coil of the second drive unit with respect to the second permanent magnet provided in the movable unit, and attracts one of the pole sides of the second permanent magnet to the coil. The movable portion is directly displaced without using a beam or the like. As described above, the optical scanner can freely displace the movable portion with a simple configuration that changes the polarity of the coil.

  Application Example 3 In the optical scanner according to the application example described above, the first permanent magnet is provided at the displacement portion so that both poles face each other in a direction orthogonal to the light reflection surface, and on the light reflection surface side. It is preferable that the respective poles positioned have different polarities.

  According to this configuration, the first permanent magnet extends in a direction orthogonal to the light reflection surface in the non-driven state, and the extending end-side pole is an N pole or an S pole. In this case, in each displacement part at both ends of the movable beam, the first permanent magnet provided in the displacement part on one side has N poles on the same side as the direction in which the light reflecting surface faces. If it is a pole, the 1st permanent magnet provided in the displacement part of the other side is arrange | positioned so that the pole of the edge part side located in the same side as the direction which the light reflective surface faces may become a S pole. Yes. That is, the poles located on the light reflecting surface side have different polarities. Here, the displacement for inclining the movable part in the optical scanner can be performed by rotating the pair of movable beams sandwiching the movable part in the same direction. In order to rotate the movable beam in this way, the coil side facing each first permanent magnet may be the S pole, and the N pole side end of the first permanent magnet may be attracted to the coil. Alternatively, the coil side facing each first permanent magnet may be an N pole, and the S pole side end of the first permanent magnet may be attracted to the coil. That is, the displacement part is rotated in the same direction. In this case, the coils of the first driving device located at both ends of the movable beam are in a state where the sides facing the movable portion have the same polarity and repel each other, and the magnetic field generated by the coils of the first driving device is the second driving It has little effect on the coil of the device. Therefore, the second driving device can individually displace the movable parts without being affected by the magnetic field of the first driving device.

  Application Example 4 In the optical scanner according to the application example described above, the second permanent magnet has a length between both poles that approximates the outer length of the movable portion, extends along the light reflecting surface, and extends the movable beam. It is preferable that the movable part is provided so that both poles face each other in a direction orthogonal to the direction.

  According to this configuration, by arranging the second permanent magnet so that both poles face each other in a direction perpendicular to the extending direction of the movable beam on a plane parallel to the light reflecting surface, the second driving device can The displacement in the direction orthogonal to the displacement applied by the first drive device can be applied to the movable part. Thus, if the displacements applied by the first drive device and the second drive device are orthogonal to each other, the displacement of the movable portion can be easily specified, and the direction of the light reflected by the movable portion can be easily controlled. Is possible. Further, the length of the second permanent magnet is approximately the same as the outer length of the movable part, and it is easy to secure a moment for rotating the movable part, and the movable part can be reliably displaced.

  Application Example 5 In the optical scanner according to the application example, it is preferable that the second permanent magnet is provided in the movable portion in a state where the light reflecting member is supported.

  According to this configuration, the second permanent magnet has a function as a support member that supports the light reflecting member having the light reflecting surface in addition to the function as the second driving device. Since the second permanent magnet supports the light reflecting member as the supporting member, the number of supporting members that only support the light reflecting member can be reduced, the magnetic field strength required for the displacement due to the weight reduction of the movable part, and the component Points can be reduced.

  Application Example 6 In the optical scanner according to the application example, it is preferable that the light reflecting surface has a larger area than the movable portion.

  According to this configuration, the light reflecting surface can be set larger than the movable portion, and for example, it can be extended from the movable portion position to a position beyond the bent portion of the movable beam, and more light flux is reflected. Is possible. This is possible because the support member has a gap between the light reflecting member having the light reflecting surface and the movable part, so that the light reflecting member can be formed in the gap even when the movable part is inclined. This is because it is possible to avoid contact with the movable beam by the amount.

  Application Example 7 An image forming apparatus according to this application example includes a light reflection member having a light reflection surface, a support member that supports the light reflection member, and a movable member that holds the light reflection member via the support member. And a pair of movable beams extending in parallel with the light reflecting surface from the movable portion and having a bent portion in the middle portion, and directly connected to the movable beam and imparting displacement to the movable portion via the movable beam A first drive device provided at each end of the movable beam in the extending direction, and extending from the displaced portion, parallel to the light reflecting surface and extending in the movable beam A pair of drive beams orthogonal to each other, a support frame for fixing the drive beams, and a second drive device that directly applies a displacement different from the first drive device to the movable portion. It is equipped with an optical scanner.

  According to this image forming apparatus, an optical scanner is provided, and according to this optical scanner, the light reflecting surface is displaced in conjunction with the movable portion and reflects incident light in an arbitrary direction. The movable portion is displaced following the operation of the movable beam driven by the displacement portion of the first driving device. Here, in a non-driven state, the movable beam has a form extending along the first axis together with the displacement portion on a surface parallel to the light reflection surface, and the displacement portion is parallel to the light reflection surface. It is supported by a driving beam extending in a direction orthogonal to the movable beam on the surface. That is, when the displacement portion rotates around the drive beam, the pair of movable beams sandwiching the movable portion respectively rotate, thereby displacing the movable portion. And the bending part provided in the movable part has a function which bends flexibly according to each rotation of a movable beam, and displaces a movable part reliably along this 1st axis. Further, the optical scanner includes a second driving device, and this second driving device is different from the first shaft due to a configuration in which the movable portion has a function of a displacement portion of the first driving device. The movable part is displaced along the second axis of the direction. That is, in the second drive device, the movable part can be displaced without using the movable beam and the drive beam. At this time, the movable beam and the bent portion function to avoid the influence of the displacement of the first drive unit or the second drive unit from reaching the other drive unit. As a result, the optical scanner can reliably move the movable portion along the first axis or the second axis with respect to the individual displacements of the first driving device or the second driving device, and can be stably and freely displaced. Is possible. In addition, since the second drive device has a configuration that does not include a movable beam and a drive beam, the optical scanner can be reduced in size. An image forming apparatus provided with such an optical scanner can stably form a free image and can be downsized.

1 is a plan view showing a configuration of an optical scanner according to the present invention. Sectional drawing which shows the structure of an optical scanner. The perspective view which shows the movable beam and drive device for displacing a reflecting plate. (A) Sectional drawing which shows the drive of the 1st drive device of an optical scanner, (b) Sectional drawing which shows the drive of a 1st drive device. (A) Sectional drawing which shows the drive of the 2nd drive device of an optical scanner, (b) Sectional drawing which shows the drive of a 2nd drive device. 1 is a schematic diagram showing an outline of an image forming apparatus of the present invention. (A) Sectional drawing which shows the modification of an optical scanner, (b) Sectional drawing which shows the drive of the 1st drive device in a modification. Sectional drawing which shows the modification of an optical scanner.

Hereinafter, an exemplary embodiment of an optical scanner and an image forming apparatus according to the present invention will be described with reference to the accompanying drawings.
(Embodiment)

  FIG. 1 is a plan view showing a configuration of an optical scanner according to the present invention. FIG. 2 is a cross-sectional view showing the configuration of the optical scanner, and shows an A-A ′ cross section of the optical scanner shown in FIG. 1. FIG. 3 is a perspective view showing a movable beam and a driving device for displacing the reflecting plate. As shown in FIGS. 1 and 2, the optical scanner 1 includes a movable portion 2, two coupling portions 11 and 12 coupled to the movable portion 2, and end portions on the opposite side to the movable portion 2 of the coupling portions 11 and 12. A first drive device 20, 30 provided to displace the movable portion 2 via the coupling portions 11, 12, a support frame 15 that supports the first drive devices 20, 30, and a support frame 15 are supported. And a second drive device 40 for directly applying a displacement different from the first drive devices 20 and 30 to the movable portion 2. The movable portion 2, the connecting portions 11 and 12, the first drive devices 20 and 30, and the support frame 15 constitute a vibration substrate 4. In addition, the movable portion 2 supports a reflection plate (light reflection member) 3 having a light reflection surface 3 a via a support member 41. In the following, as shown in FIG. 1 in plan view of the optical scanner 1, the longitudinal direction of the vibration substrate 4 from which the connecting portions 11 and 12 extend is defined as the X axis (the first axis in the means for solving the problem). ), The plane formed by the X axis and the Y axis (the second axis in the means for solving the problem) is parallel to the non-driven light reflecting surface 3a, and the Z axis orthogonal to the plane is This coincides with the thickness direction of the reflecting plate 3 having the light reflecting surface 3a.

  First, the vibration substrate 4 will be described. The support frame 15 of the vibration substrate 4 has a frame shape to support the movable part 2 and is provided so as to surround the periphery of the movable part 2. The movable portion 2 connected to the inside of the support frame 15 by the connecting portions 11 and 12 has a circular flat plate shape, and the reflecting plate 3 supported by the movable portion 2 has a diameter (outer length) of the movable portion 2. ) Having a diameter D1 of approximately the same size (approximate) as that in FIG. The light reflecting surface 3a is obtained, for example, by forming a metal film such as gold, silver, or aluminum by vapor deposition or the like. In this case, the light reflecting surface 3a is formed of aluminum.

  The connecting portions 11 and 12 are symmetrically formed along the X-axis direction with respect to the movable portion 2, and the connecting portion 11 connects the displacement portion 21, the displacement portion 21 and the support frame 15. It has a pair of drive beams 9, and a movable beam 5 that connects the displacement portion 21 and the movable portion 2 and has a bent portion 7 at an intermediate portion. The connecting portion 12 connects the displacement portion 31, the pair of driving beams 10 that connect the displacement portion 31 and the support frame 15, and the movable portion 2 that connects the displacement portion 31 and the movable portion 2, and has a bent portion 8 at an intermediate portion. And a beam 6.

  Here, the detailed structure of the connection parts 11 and 12 is demonstrated with reference to FIG. 3 for the connection part 11 as an example. The connecting portion 12 has the same configuration as the connecting portion 11. As shown in FIG. 3, the pair of drive beams 9 are disposed to face each other in the Y-axis (FIG. 1) direction via the displacement portion 21, and support the displacement portion 21 at both ends. Further, each of the drive beams 9 has a rod shape extending in the Y-axis direction, and is configured to be torsionally deformed around the Y-axis direction. Such a drive beam 9 is provided coaxially, and the displacement part 21 rotates (displaces) by each torsionally deforming centering on this axis | shaft.

  The displacement portion 21 is provided so as to be separated from the movable portion 2 in the X-axis direction (FIG. 1), and the displacement body 211 of the displacement portion 21 is supported at both ends by the pair of drive beams 9. Further, a through hole 212 is formed in the displacement body 211, and the first permanent magnet 213 is inserted into the through hole 212 and is fixed by fitting (press fitting) or an adhesive. Furthermore, the planar view shape of the displacement portion 21 is a rectangle whose longitudinal direction is the Y-axis direction, and the width of the displacement body 211 (length in the X-axis direction) is secured while securing a space for fixing the first permanent magnet 213. Can be suppressed. By suppressing the width of the displacement body 211, the moment of inertia generated when the displacement body 211 rotates about the Y-axis direction can be suppressed, the reactivity of the displacement portion 21 is increased, and faster rotation is achieved. It becomes possible. Further, when the reactivity of the displacement portion 21 is increased, it is possible to suppress the occurrence of unintentional vibration due to the rotation of the displacement portion 21, and this is particularly effective when the rotation direction is switched. Therefore, the optical scanner 1 can be driven stably.

  The displacement portion 21 is connected to the movable portion 2 by the movable beam 5. The movable beam 5 is provided so as to extend in the X-axis direction. The bending portion 7 described above, the movable portion side beam 5a that connects the bending portion 7 and the movable portion 2, and the bending portion 7 are displaced. A displacement portion side beam 5b that connects the displacement body 211 of the portion 21. The movable part side beam 5a and the displacement part side beam 5b each have a rod shape extending in the X-axis direction, and are provided coaxially.

  Of the movable beam 5, the displacement portion side beam 5b is preferably set to a hardness that does not cause a large deformation when the optical scanner 1 is driven, and more preferably set to a hardness that does not substantially deform. preferable. On the other hand, the movable part side beam 5a has a form capable of torsional deformation around an axis centered on the beam extending in the X-axis direction. Thus, by having the displacement part side beam 5b, which is a hard part where the movable beam 5 is not substantially deformed, and the movable part side beam 5a, which is a part that can be torsionally deformed, the movable part 2 can be moved along the X axis and It can be stably rotated around each axis of the Y axis. Here, “does not deform” means that bending or bending in the Z-axis direction and torsional deformation about an axis with a beam as an axis do not substantially occur. The movable portion side beam 5a and the displacement portion side beam 5b are connected via the bent portion 7, and the bent portion 7 functions as a node when the movable beam 5 is bent and deformed. A function of relaxing (absorbing) torque generated by torsional deformation of the beam 5a and preventing or suppressing transmission of the torque to the displacement portion side beam 5b is achieved.

  The bent portion 7 has a non-deformed portion 71 and a stress relaxation portion 72. The stress relaxation portion 72 includes a pair of deformation portions 721 provided on the movable portion side beam 5a side and the displacement portion side beam 5b side of the non-deformation portion 71, and the deformation portion 721 as the non-deformation portion 71. A connection portion 722 for connection. The non-deformable portion 71 has a rod shape extending in the Y-axis direction, and is set to a hardness that does not substantially deform when the optical scanner 1 is driven. With this configuration, the movable beam 5 can be bent around the non-deformable portion 71. That is, it is possible to cause the stress relaxation unit 72 to reliably function as a node and to stably drive the optical scanner 1.

  Further, the pair of deformable portions 721 are arranged symmetrically with respect to the non-deformed portion 71, form a rod shape extending in the Y-axis direction, and are arranged in parallel with each other in the X-axis direction. These deformable portions 721 are in a form that can be twisted and deformed around their respective central axes. And the deformation | transformation part 721 located in the movable part 2 side is connected with the end of the movable part side beam 5a in the approximate center of the longitudinal direction, and via a pair of connection part 722 in the both ends. The non-deformable portion 71 is connected. Similarly, the deformation portion 721 located on the displacement portion 21 side is connected to one end of the displacement portion side beam 5b at substantially the center in the longitudinal direction, and at both ends via a pair of connection portions 722. And connected to the non-deformable portion 71. These connecting portions 722 have a rod shape extending in the X-axis direction, can be curved in the Z-axis direction, and can be twisted around the central axis. With the connecting portion 11 having such a configuration, the movable portion 2 can be rotated more smoothly around the X-axis direction or the Y-axis direction as a central axis.

  On the other hand, the connecting portion 12 also has the same function as the connecting portion 11, and includes a movable beam 6 (movable portion side beam 6 a and displacement portion side beam 6 b), a bent portion 8, and a displacement portion 31 (displacement body 311). , The through hole 312, the first permanent magnet 313), and the drive beam 10.

In the optical scanner 1 having such a configuration, the vibration substrate 4 is integrally formed by etching the SOI substrate. The SOI substrate is a substrate in which a first Si layer, a SiO ₂ layer, and a second Si layer are stacked in this order. The vibration substrate 4 includes a portion that is positively deformed and a portion that is not deformed (does not want to be deformed). Therefore, the portion not to be deformed is constituted by all the three layers, and the portion to be positively deformed is constituted by only the second Si layer or _two layers of the second Si layer and the SiO ₂ layer. That is, by changing the thickness of the SOI substrate, it is possible to easily form the vibration substrate 4 in which a portion to be deformed and a portion not to be deformed are mixed.

  The vibration substrate 4 in the optical scanner 1 is supported by a base 16 as shown in FIG. The base 16 has a box shape (a bowl shape), and is provided at a flat plate-like base portion 161, a frame portion 162 erected along an edge portion of the base portion 161, and both end portions in the X-axis direction. And a placement portion 163 on which the coil portions (first drive portions) 22 and 32 to be placed are placed. In such a base 16, the frame portion 162 is joined to the support frame 15 of the vibration substrate 4 to support the vibration substrate 4. The base 16 is composed mainly of glass or silicon, and in this case, is formed of silicon. The base 16 and the support frame 15 are joined using an adhesive. However, the joining is not limited to this, and various joining methods such as anodic joining may be used.

  Next, a configuration in which the movable portion 2 and the reflection plate 3 are displaced by the displacement of the displacement portions 21 and 31, and a configuration in which a displacement different from the displacement by the displacement portions 21 and 31 is applied to the movable portion 2 and the reflection plate 3 explain. First, the displacement of the displacement parts 21 and 31 will be described.

  As shown in FIGS. 1 and 2, the first drive device 20 having the displacement portion 21 is a coil portion (first drive portion) 22 provided opposite to the movable portion 2 with respect to the displacement portion 21. The first drive device 30 having the displacement part 31 has a coil part (first drive part) 32 provided opposite to the movable part 2 with respect to the displacement part 31. The first drive device 20 is provided to be connected to the connection portion 11, and the first drive device 30 is provided to be connected to the connection portion 12. Since the first drive devices 20 and 30 have the same configuration and the same function, the case of the first drive device 20 will be described.

  In the first drive device 20, the first permanent magnet 213 of the displacement portion 21 has a rod shape and is magnetized in the longitudinal direction thereof. That is, the first permanent magnet 213 has an S pole on one end side in the longitudinal direction and an N pole on the other end side. In this case, the same direction side as the direction of the light reflecting surface 3a is the S pole. . The first permanent magnet 213 is inserted through the through hole 212 of the displacement body 211 in the Z-axis direction, and is bonded and fixed to the displacement body 211 at a substantially central position in the longitudinal direction. As this first permanent magnet 213, a neodymium magnet, a ferrite magnet, a samarium cobalt magnet, an alnico magnet, a bonded magnet or the like magnetized with a hard magnetic material can be used. In this case, a neodymium magnet is used. ing.

  The coil portion 22 includes a coil fixing portion 222 mounted on the mounting portion 163 of the base 16 and a coil 221 wound around a portion protruding in the X-axis direction of the coil fixing portion 222. The protruding portion is configured to generate a magnetic field more efficiently by forming a soft magnetic material such as iron as a magnetic core. In addition, the coil 221 generates a magnetic field in the X-axis direction that acts on the first permanent magnet 213, a state in which the first permanent magnet 213 side of the coil portion 22 is an N pole and the opposite side is an S pole, It is possible to generate a state in which the first permanent magnet 213 side becomes the S pole and the opposite side becomes the N pole.

  A magnetic field can be generated by applying a voltage to the coil 221 from a power source (not shown) that is electrically connected to the coil 221. Here, an alternating voltage and a direct-current voltage can be selected and applied as the power source, and the strength and frequency can be changed when the alternating voltage is applied. Furthermore, an offset voltage (DC voltage) can be superimposed.

  Also in the first drive device 30, the first permanent magnet 313 of the displacement portion 31 and the coil 321 and the coil fixing portion 322 of the coil portion (first drive portion) 32 have the same action as the first drive device 20. Has an effect. In this case, the first permanent magnet 313 has an arrangement in which the same direction as the direction in which the light reflecting surface 3a faces is an N pole, and has a different polarity arrangement from the first permanent magnet 213 of the first driving device 20. ing. That is, the first permanent magnet 213 and the first permanent magnet 313 have polarities different from each other on the light reflecting surface 3a side.

  Following the displacement of the displacement parts 21 and 31, the rotation of the movable part 2 by the first drive devices 20 and 30 will be described. In this case, the movable part 2 rotates around an axis about the Y-axis direction. FIG. 4A is a cross-sectional view showing driving of the first drive device of the optical scanner. FIG. 4B is a cross-sectional view illustrating driving of the first driving device, and illustrates driving in a direction different from that in FIG. FIG. 4 is a cross-sectional view corresponding to the cross section A-A ′ in FIG. 1. First, a first state in which the first permanent magnet 213 side of the coil portion 22 is the S pole and the first permanent magnet 313 side of the coil portion 32 is also the S pole, and the first permanent magnet 213 side of the coil portion 22 is the N pole, the coil The alternating voltage from the power source to the coils 221 and 321 (FIG. 2) from the power source so that the second state in which the first permanent magnet 313 side of the portion 32 is also N-pole is alternately and periodically switched. Is applied. In the optical scanner 1, it is preferable that the alternating voltages have the same waveform, that is, the same strength and frequency.

  In the first state shown in FIG. 4A, the N pole of the first permanent magnet 213 is attracted to the coil part 22 and the S pole moves away from the coil part 22, so that the displacement body 211 moves the pair of drive beams 9. While being torsionally deformed, the first permanent magnet 213 is rotated and inclined so that the surface on the S pole side of the first permanent magnet 213 faces the movable portion 2 side. At the same time, the N pole of the first permanent magnet 313 is attracted to the coil part 32 and the S pole moves away from the coil part 32, so that the displacement body 311 twists and deforms the pair of drive beams 10 while The permanent magnet 313 is rotated and tilted so that the surface on the S pole side of the permanent magnet 313 faces the movable portion 2 side. That is, both the displacement parts 21 and 31 rotate clockwise in FIG.

  Along with the rotation of the displacement parts 21 and 31, the displacement part side beam 5b is inclined so that the end on the movable part 2 side is directed toward the base 16 side, and the displacement part side beam 6b is the base on the movable part 2 side. Inclined so as to be directed to the opposite side of 16, and the ends of the displacement parts 21, 31 on the movable part 2 side are shifted in the Z axis direction. As a result, the deformed portion 721 of the bent portion 7 is torsionally deformed around its central axis, and the connecting portion 722 is curvedly deformed. The bent portion 8 is similarly twisted and bent, and the movable portion side beams 5a and 6a and the movable portion 2 are integrally rotated counterclockwise in FIG.

  On the other hand, in the second state shown in FIG. 4B, the deformation opposite to the first state described above occurs. That is, the S pole of the first permanent magnet 213 is attracted to the coil part 22 having the N pole, and the S pole of the first permanent magnet 313 is attracted to the coil part 32 having the N pole. The movable part 2 rotates clockwise in FIG. In this way, by alternately and periodically switching between the first state and the second state, the movable part 2 can be freely rotated about an axis about the Y-axis direction. .

  Next, the structure which gives the displacement different from the displacement by the displacement parts 21 and 31 to the movable part 2 and the reflecting plate 3 is demonstrated. FIG. 5A is a cross-sectional view showing driving of the second drive device of the optical scanner. FIG. 5B is a cross-sectional view showing driving of the second driving device, and shows driving in a direction different from that in FIG. FIG. 5 is a cross-sectional view corresponding to the B-B ′ cross section in FIG. 1, and will be described below with reference to FIGS. 1, 2, and 3 in addition to FIG. 5. In this case, the movable part 2 and the reflecting plate 3 are rotated around an axis with the X-axis direction as an axis, and this rotation of the movable part 2 is performed by the second driving device 40.

  The second driving device 40 includes a support member 41 that is a second permanent magnet that is provided in the movable portion 2 and supports the reflector 3, and a coil portion that is provided in the base portion 161 of the base 16 so as to face the movable portion 2. (Second drive unit) 42. The support member 41, which is a second permanent magnet, has a rod shape that is approximately the same length as the diameter of the movable portion 2, and is disposed along the Y-axis direction of the reflector 3 in a non-driven state. The movable portion 2 is provided with an alignment guide 2a which is a groove for arranging the support member 41 at an accurate position, so that the support member 41 can be easily mounted.

  The coil portion 42 includes a coil fixing portion 422 placed on the base portion 161 and a coil 421 wound around a portion of the coil fixing portion 422 protruding in the Z-axis direction. The protruding part has a soft magnetic material such as iron as a magnetic core, and can generate a magnetic field more efficiently. The coil 421 is electrically connected to a power source (not shown) and generates a magnetic field in the Z-axis direction that acts on the support member 41 that is the second permanent magnet. The state where the side is the N pole and the opposite side is the S pole and the state where the opposite polarity is arranged can be switched alternately and periodically.

  As shown in FIG. 5A, in the coil portion 42, when the side of the support member 41 that is the second permanent magnet is an N pole, the S pole of the support member 41 is attracted to the coil portion 42 and the N pole is a coil. In order to move away from the portion 42, the movable portion 2 tilts counterclockwise while twisting and deforming the movable portion side beams 5a and 6a. On the other hand, as shown in FIG. 5B, in the coil portion 42, when the side of the support member 41 that is the second permanent magnet is the south pole, the north pole of the support member 41 is attracted to the coil portion 42. Since the south pole moves away from the coil part 42, the movable part 2 rotates clockwise and tilts while twisting and deforming the movable part side beams 5a and 6a. Then, the counterclockwise rotation or the clockwise rotation of the movable portion 2 is absorbed by the twist of the movable portion side beams 5a and 6a, and the rotation of the movable portion 2 by the first driving devices 20 and 30 is performed. Does not affect movement.

  Further, in the first driving devices 20 and 30, the coil part 22 and the coil part 32 are connected to the movable part 2 because the poles on the light reflecting surface 3 a side of the first permanent magnets 213 and 313 are different from each other. The poles on the side facing each other are in the same polarity. That is, the coil part 22 and the coil part 32 are always in a state of repulsion. Thereby, the coil part 42 of the 2nd drive device 40 provided in the base 161 near the movable part 2 cancels the magnetic field from the coil part 22 and the coil part 32, and is hardly influenced by these magnetic fields. It will be.

  Therefore, in the optical scanner 1, the rotation of the movable part 2 about the axis in the Y-axis direction and the rotation of the movable part 2 about the axis in the X-axis direction can be performed independently of each other. That is, the rotation of the movable part 2 by the first driving devices 20 and 30 is not affected by the rotation of the movable part 2 by the second driving device 40, and conversely, the rotation of the movable part 2 by the second driving device 40. The movement is not affected by the rotation of the movable part 2 by the first driving devices 20 and 30. Therefore, the optical scanner 1 can stably rotate the movable part 2 around the respective axes in the Y-axis direction and the X-axis direction.

  The optical scanner 1 as described above can be suitably applied to an image forming apparatus such as a projector, a laser printer, an imaging display, a barcode reader, and a scanning confocal microscope. FIG. 6 is a schematic diagram showing an outline of the image forming apparatus of the present invention. FIG. 6 shows a projector 100 as an image forming apparatus. Here, the longitudinal direction of the screen 180 is referred to as “lateral direction”, and the direction perpendicular to the longitudinal direction is referred to as “vertical direction”. The projector 100 includes a light source device 110 that emits light such as a laser, a plurality of dichroic mirrors 120, and the optical scanner 1.

  The light source device 110 includes a red light source device 111 that emits red light, a blue light source device 112 that emits blue light, and a green light source device 113 that emits green light. Each dichroic mirror 120 is an optical element that combines light emitted from each of the red light source device 111, the blue light source device 112, and the green light source device 113. Such a projector 100 combines light emitted from the light source device 110 with a dichroic mirror 120 based on image information from a host computer (not shown), and the combined light is two-dimensionally scanned by the optical scanner 1. A color image is formed on the screen 180 via the fixed mirror 150.

  During two-dimensional scanning, the movable portion 2 of the optical scanner 1 rotates about the axis in the Y-axis direction, and the light reflected by the light reflecting surface 3a of the reflecting plate 3 scans in the horizontal direction of the screen 180 (main scanning). Is done. On the other hand, the movable part 2 of the optical scanner 1 rotates around the axis in the X-axis direction, and the light reflected by the light reflecting surface 3a is scanned (sub-scanned) in the vertical direction of the screen 180. The scanning of light by the optical scanner 1 may be performed by so-called raster scanning, or may be performed by so-called vector scanning. In particular, since the optical scanner 1 is suitable for vector scanning because of its configuration, it is preferable to scan light by vector scanning.

  Vector scanning preferable for the optical scanner 1 is a method of scanning the light emitted from the light source device 110 so as to sequentially form line segments connecting two different points on the screen 180 with respect to the screen 180. In other words, this is a method for forming a desired image on the screen 180 by collecting minute straight lines. The optical scanner 1 is particularly suitable for vector scanning because the movable part 2 can be displaced irregularly and continuously around the axis in the Y-axis direction and the axis in the X-axis direction.

  More specifically, when characters (a and b) as shown in FIG. 6 are drawn by vector scanning, light emitted from the light source device 110 is scanned so as to write each character. At this time, the posture (rotation) around the axis in the X-axis direction and the posture (rotation) around the axis in the Y-axis direction of the movable part 2 of the optical scanner 1 are controlled respectively along the scanning locus 130. Light can be scanned irregularly, and the letters a and b can be drawn like a single stroke. According to such a vector scan, it is not necessary to scan the entire surface of the screen 180 as in the case of a raster scan, so that an image can be efficiently drawn. In FIG. 6, the light synthesized by the dichroic mirror 120 is scanned two-dimensionally by the optical scanner 1, and then the light is reflected by the fixed mirror 150 and then formed on the screen 180. However, the fixed mirror 150 may be omitted, and the screen 180 may be directly irradiated with light two-dimensionally scanned by the optical scanner 1.

  The main effects of the optical scanner 1 in the embodiment described above will be described.

  (1) The optical scanner 1 has a function of giving displacement to the movable part 2 without the first driving devices 20 and 30 and the second driving device 40 being affected by each other. Thus, in the optical scanner 1, the movable portion 2 can be individually and stably rotated about the axis in the X-axis direction or the Y-axis direction, and light can be reflected in an arbitrary direction. Furthermore, since the second drive device 40 is configured not to have a movable beam and a drive beam, the optical scanner 1 can be further downsized.

  (2) The first driving devices 20 and 30 of the optical scanner 1 include first permanent magnets 213 and 313 and coils 221 and 321, and the second driving device 40 includes a support member 41 that is a second permanent magnet. A coil 421. Then, a magnetic field is generated from the coils 221, 321 or the coil 421 with respect to the first permanent magnets 213, 313 or the support member 41, and any one of the first permanent magnets 213, 313 or the support member 41 is used as a coil. The movable part 2 is rotated by attracting. As described above, the optical scanner 1 can easily displace the movable part 2 with a configuration in which the polarities of the coils 221, 321, and 421 are simply changed by applying a voltage.

  (3) In the optical scanner 1, the first permanent magnets 213 and 313 have polarities different from each other on the light reflecting surface 3 a side, and the first permanent magnets 213 and 313 are positioned at both ends of the movable beams 5 and 6, respectively. A voltage is applied to the coils 221 and 321 of the first driving devices 20 and 30 such that the respective poles on the side facing the first permanent magnets 213 and 313 have the same polarity. That is, the coils 221 and 321 are in a state of repelling each other. Therefore, the magnetic field generated by the coils 221 and 321 hardly affects the coil 421 of the second drive device 40. Thereby, the 2nd drive device 40 can rotate the movable part 2 separately by making the X-axis direction into a central axis, hardly receiving the influence of the magnetic field of the 1st drive devices 20 and 30. FIG.

  (4) The optical scanner 1 functions as a second permanent magnet in addition to the support member 41 supporting the reflector 3. As a result, the optical scanner 1 can reduce the number of supporting members that only support the reflecting plate 3, reduce the weight of the movable portion 2, reduce the magnetic field strength required for displacement, reduce the number of components, and the like.

  Further, the optical scanner 1 and the projector 100 as the image forming apparatus are not limited to the above-described embodiment, and the same effects as those of the embodiment can be obtained even in the following modifications. .

  (Modification 1) The reflector 3 of the optical scanner 1 has a circular shape with a diameter D1 that is approximately the same size as the movable portion 2, but is not limited to this configuration, and the movable beams 5 and 6 function. As long as it is within the range, it may be a circle having a larger diameter D2 than the movable portion 2. FIG. 7A is a cross-sectional view showing a modified example of the optical scanner, and FIG. 7B is a cross-sectional view showing driving of the first drive device in the modified example. As shown in FIG. 7A, the reflecting plate (light reflecting member) 50 supported on the movable portion 2 by the support member 41 has a light reflecting surface 50a in the opposite direction to the movable portion 2. The circumferential end portion has a size that reaches the displacement portion side beams 5b and 6b beyond the bent portions 7 and 8. Even in the reflector 50 having such a size, the light reflecting surface 50a is separated from the movable portion 2 by the support member 41. Therefore, as shown in FIG. Even when the reflecting plate 50 is rotated and tilted, the movable beams 5 and 6 and the bent portions 7 and 8 do not come into contact with each other. That is, the reflecting plate 50 can rotate in the same manner as the reflecting plate 3 and can reflect more light fluxes at a time. In contrast, the reflecting plate may be a circle smaller than the movable portion 2.

  (Modification 2) The support member 41 has a function of supporting the reflecting plate 3 to the movable part 2 and a function of displacing the movable part 2 as the second permanent magnet of the second driving device 40. You may have these functions separately. FIG. 8 is a cross-sectional view showing a modification of the optical scanner. As shown in FIG. 8, the reflector 3 is supported on the movable part 2 by a support member 3 b formed of cylindrical silicon or the like, and the support member 41 that is a second permanent magnet is on the coil part 42 side of the movable part 2. A configuration may be adopted in which the movable portion 2 is displaced as a magnet by being attached to a groove of the alignment guide 2b formed on the surface. That is, the support member 41 specializes in the function as the second permanent magnet. Thus, in the second drive device 40, the support member 41, which is a permanent magnet, and the coil portion 42 directly face each other, and can be displaced more reliably and quickly.

  (Modification 3) In the optical scanner 1, the planar view shape of the movable portion 2 and the reflector 3 is circular, but is not limited to this, and is, for example, a polygon such as a rectangle or a square, a circle or an ellipse. May be. Moreover, the movable part 2 and the reflecting plate 3 may not be the same shape.

  (Modification 4) The plan view shape of the displacement bodies 211 and 311 of the displacement portions 21 and 31 is not particularly limited, and may be, for example, a square or a polygon more than a pentagon, or a circle or the like. Also good.

  (Modification 5) Although the 1st permanent magnets 213 and 313 in the displacement parts 21 and 31 have comprised rod shape, it is not limited to this, For example, plate shape etc. may be comprised. In the case of a plate shape, these permanent magnets are magnetized in the surface direction and fixed to the displacement bodies 211 and 311. As a result, the length of the permanent magnet in the X-axis direction can be shortened, and the moment of inertia generated with the rotation of the displacement bodies 211 and 311 can be suppressed.

  (Modification 6) In the optical scanner 1, the first permanent magnet 213 and the first permanent magnet 313 have the polarities of the respective poles located on the light reflecting surface 3a side different from each other, and the movable portion 2 is moved to X. Although it is the structure rotated about the axis of an axial direction or a Y-axis direction, you may give displacement other than rotation by changing the arrangement | positioning of a magnet and the application method of a voltage. For example, the movable unit 2 can be vibrated or stopped in the Z-axis direction without being inclined, and more various light reflections can be performed.

  (Modification 7) The first drive devices 20 and 30 and the second drive device 40 include a support member 41 that is the first permanent magnet 213, 313 or the second permanent magnet, the coil portions 22, 32, or the coil portion 42, However, instead of the coil portions 22, 32, 42, for example, a configuration having a permanent magnet rotatably installed may be used. By rotating the permanent magnet quickly, the polarity on the side facing the support member 41 which is the first permanent magnet 213, 313 or the second permanent magnet can be changed like the coil portions 22, 32, 42. .

  (Modification 8) In the optical scanner 1, the vibration form in the vibration substrate 4 is not particularly defined. For example, when the movable unit 2 is rotated by the first driving devices 20 and 30 via the coupling units 11 and 12. In this case, it is preferable that each drive is resonated. In the resonance drive, the same rotation is repeated to drive the movable part 2 in a sine wave. Is possible. On the other hand, when the movable unit 2 is directly rotated by the second driving device 40 without using a beam or the like, the second driving device 40 and the movable unit side beams 5a and 6a that support the rotation of the movable unit 2 are provided. However, the non-resonant driving increases power consumption, but the movable part 2 can be freely driven with a small rotation. By selecting resonance driving or non-resonance driving, the optical scanner 1 can be driven optimally and can be mounted on various image forming apparatuses including the projector 100.

  DESCRIPTION OF SYMBOLS 1 ... Optical scanner, 2 ... Movable part, 3 ... Reflecting plate as light reflecting member, 4 ... Vibration board, 5, 6 ... Movable beam, 7, 8 ... Bending part, 9, 10 ... Drive beam, 11, 12 ... Connection part 20 ... 1st drive device, 21 ... Displacement part, 22 ... Coil part as 1st drive part, 30 ... 1st drive device, 31 ... Displacement part, 32 ... Coil part as 1st drive part, 40 DESCRIPTION OF SYMBOLS ... 2nd drive device, 41 ... Support member as 2nd permanent magnet, 42 ... Coil part as 2nd drive part, 100 ... Projector as image forming apparatus, 213 ... 1st permanent magnet, 313 ... 1st permanent magnet .

Claims (7)

A light reflecting member having a light reflecting surface;
A support member for supporting the light reflecting member;
A movable part holding the light reflecting member via the support member;
A pair of movable beams each extending in parallel with the light reflecting surface from the movable portion, and having a bent portion at an intermediate portion;
A displacement part connected to the movable beam and applying displacement to the movable part via the movable beam;
A first drive unit for driving the displacement unit;
A pair of drive beams extending from the displacement portion, parallel to the light reflecting surface and orthogonal to the extending direction of the movable beam;
A support frame connected to the displacement part by the drive beam;
An optical scanner, comprising: a second driving unit that applies a displacement to the movable unit that is different from a displacement applied by the displacement unit driven by the first driving unit. The optical scanner according to claim 1.
The displacement part has a first permanent magnet,
The first driving unit includes a coil that generates a magnetic field acting on the first permanent magnet,
The movable part has a second permanent magnet,
The optical scanner, wherein the second driving unit includes a coil that generates a magnetic field that acts on the second permanent magnet. The optical scanner according to claim 2,
The first permanent magnet is provided at the displacement portion so that both poles face each other in a direction orthogonal to the light reflecting surface, and the respective poles located on the light reflecting surface side have different polarities. An optical scanner characterized by The optical scanner according to claim 2 or 3,
The second permanent magnet is movable so that the length between the two poles approximates the outer length of the movable portion, and the two poles face each other along the light reflecting surface and perpendicular to the extending direction of the movable beam. An optical scanner characterized in that it is provided in the section. The optical scanner according to any one of claims 2 to 4,
The optical scanner, wherein the second permanent magnet is provided on the movable portion in a state where the light reflecting member is supported. The optical scanner according to any one of claims 1 to 5,
The light scanner, wherein the light reflecting surface has a larger area than the movable portion. A light reflecting member having a light reflecting surface;
A support member for supporting the light reflecting member;
A movable part holding the light reflecting member via the support member;
A pair of movable beams each extending in parallel with the light reflecting surface from the movable portion, and having a bent portion at an intermediate portion;
A displacement part connected to the movable beam and applying displacement to the movable part via the movable beam;
A first drive unit for driving the displacement unit;
A pair of drive beams extending from the displacement portion, parallel to the light reflecting surface and orthogonal to the extending direction of the movable beam;
A support frame connected to the displacement part by the drive beam;
An image forming apparatus comprising: an optical scanner having a second drive unit that applies a displacement different from the displacement applied by the displacement unit driven by the first drive unit to the movable unit. .

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